The reflections 2 (FIG. 1) of the sun 2, sky or other bright source from a surface 4 of a transparent member, such as a window of a building or motor vehicle (e.g., automotive windshield) have long been a problem in a number of cases because they tend to obscure the target or object one is attempting to view through the reflective surface. For example, when a police officer, federal law enforcement official or other authorized person (e.g., soldier) is trying to view a target area that is behind the transparent member, the view is obscured by the reflections 6. This obstruction of the view occurs because such reflections 6 of the sun 2 or the sky can be much brighter than the image of the target area that lies behind the transparent member surface 4.
This obstruction of the view is particularly dangerous in hostage type of situations because the reflections 6 can obscure the police officer's, federal official's or military personnel's view of the target area. This problem can be especially dangerous during situations such as hostage crisis area, because it can prevent the police officer, federal official or soldier from determining who is a hostage and who is the hostage taker.
The reflections 6 of the sun 2 from the surface 4 are mainly in the form of linearly polarized rays 8. Accordingly, one method for reducing or eliminating the effect of such linearly polarized reflections or rays 8 from the transparent surface 4 involves placing a polarizing filter in front of the optical device or optical lens assembly being used to view the target area. The polarizing filter suppresses the reflections and provides a clearer view to the subject beyond the surface causing the reflections. For example, fishermen use polarized sunglasses to suppress the reflections from the water's surface so they can better see their prey. In another example, photographers use a polarizing filter mounted on the front of the camera lenses to suppress reflections from building windows.
When this particular technique is applied to a sight for a weapon such as a rifle of a police officer or federal official, which is the common practice, other problems can arise. For example, when a polarizing filter is mounted in front of an optical system of the weapon sight, the polarizing filter can act like an optical wedge, thus refracting the light rays entering the optical system of the weapon sight thereby causing the image to be shifted slightly. Because this image shifting occurs before the image gets to the reticle or reticule provided within the optical system of the weapon sight, this shifting changes the point of impact for a projectile fired from the weapon as projected by the weapon sight. This can result, consequently, in the shooter not hitting the intended target at all or where intended or possibly striking another when the intended target is missed altogether (e.g., wrong target or bystander).
A missed shot or not hitting the target where intended can be dangerous particularly such as when dealing with a hostage crisis. This also applies in the case where a shot is not taken at all because of the targeting uncertainty created by the particular method or device used to attenuate the surface reflections. In such cases the inability or failure to take a shot or to take the intended shot can lead to the loss of life or serious injury to the hostages or innocent bystanders.
It thus would be desirable to provide a new method, technique and device that reduces or attenuates the reflections from the surface of a transparent member. It would be particularly desirable to provide new methods and devices that minimize the effect of such reflections while viewing an object or target through the reflective surface of the transparent member by a weapon sight without affecting the projected point of impact of the projectile from the weapon sight or other telescopic viewing mechanism. Such methods and devices preferably would be simple in construction and would not require highly skilled users to utilize the device or require sophisticated or detailed procedures for using such a device in the field.